In recent years, in a fixing device using a resistance heat generating element, it is studied to dispose a heat generating unit, in which a heat generating region is divided into a plurality of portions, in a main scanning direction and selectively generate heat in the heat generating region corresponding to a sheet size (JP-A-2015-028531). However, if the heat generating region of the resistance heat generating element is divided, there is a problem that a temperature decreases at a connection portion between adjacent regions.
In a fixing device for electrophotography, if heat generation unevenness occurs in a direction perpendicular to a sheet transporting direction, the fixing quality is affected. In particular, for color printing, a difference in coloring and gloss may occur.
In general, according to one embodiment, there is provided a heater and a fixing device capable of preventing a temperature decrease in a connection portion between adjacent regions if a heat generating region of a resistance heat generating element is divided.